scholarly journals 204 Effect of segregation of solute atoms on grain boundary γ-surface in aluminum from the first-principles calculations

2008 ◽  
Vol 2008.21 (0) ◽  
pp. 137-138
Author(s):  
Tokuteru UESUGI ◽  
Yasuhiko INOUE ◽  
Kenji HIGASHI
Keyword(s):  
Grain Boundary ◽  
First Principles ◽  
First Principles Calculations ◽  
Solute Atoms

First-Principles Investigation of Intergranular Fracture in Copper by Grain Boundary Segregation of Sulfur

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Xudong Wang ◽  
Lahouari Benabou
Keyword(s):  
Grain Boundary ◽  
First Principles ◽  
Cohesive Energy ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
First Principles Calculations ◽  
Order Of Magnitude ◽  
Symmetrical Tilt ◽  
Solute Atoms ◽  
Tilt Grain Boundary

Grain boundary (GB) embrittlement by sulfur in fcc CuΣ5(012)[100] symmetrical tilt grain boundary (STGB) is simulated by first-principles calculations. The surface and grain boundary segregation energies are estimated by progressively placing solute atoms in the potential segregation sites in the boundaries. Based on the calculated segregation energies, the cohesive energy of the grain boundary is evaluated as a function of the sulfur atoms concentration. It is found that, when a two atomic layers’ concentration is attained, the cohesive energy is reduced by one order of magnitude compared to its value for the clean grain boundary.

Defect chemistry of a BaZrO3 Σ3 (111) grain boundary by first principles calculations and space–charge theory

2012 ◽  
Vol 14 (35) ◽  
pp. 12339 ◽  
Author(s):  
Jonathan M. Polfus ◽  
Kazuaki Toyoura ◽  
Fumiyasu Oba ◽  
Isao Tanaka ◽  
Reidar Haugsrud
Keyword(s):  
Grain Boundary ◽  
Space Charge ◽  
First Principles ◽  
Defect Chemistry ◽  
First Principles Calculations

First Principles Calculations on ∑ 3 Grain Boundary Impurities in Polycrystalline Silicon

2009 ◽  
Author(s):  
A. Suvitha ◽  
N. S. Venkataramanan ◽  
R. Sahara ◽  
H. Mizuseki ◽  
Y. Kawazoe
Keyword(s):  
Grain Boundary ◽  
First Principles ◽  
Polycrystalline Silicon ◽  
First Principles Calculations

Properties of Iron Atoms at Grain Boundaries in Fe and Fe72Al28

1998 ◽  
Vol 527 ◽  
Author(s):  
O. Schneeweiss ◽  
I. Turek ◽  
J. Čermák ◽  
P. Lejček
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Single Crystals ◽  
First Principles ◽  
Magnetic Moments ◽  
Emission Mössbauer Spectroscopy ◽  
First Principles Calculations ◽  
Hyperfine Parameters ◽  
Impurity Atoms ◽  
Atomic Spacing

ABSTRACTLocation of diffused 57Co atoms in single crystals, bicrystals and polycrystals of pure iron and Fe72Al28alloy were investigated by means of emission Mössbauer spectroscopy. To interpret the results, first principles calculations of iron atom magnetic moments and hyper-fine field were carried out. From comparison of M6ssbauer spectra of single crystals with those of bicrystals and polycrystals, an information about grain boundary positions occupied by diffusing atoms is obtained. It is shown that about 5% of the diffusing atoms at the {112} grain boundary of iron are located at the positions either having impurity atoms in the nearest neighbourhood or characterized by larger atomic spacing in comparison with the bulk. In the Fe72Al28 a dominating portion of diffusing atoms have different surrounding than in grain volume. An enrichment of grain boundaries by aluminum could explain their hyperfine parameters.

First-Principles Calculations of Grain Boundary-Surface for Various Grain Boundaries with Different Energies in Aluminum

2007 ◽  
Vol 551-552 ◽  
pp. 331-336 ◽  
Author(s):  
Tokuteru Uesugi ◽  
Y. Inoue ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Shear Strength ◽  
Grain Boundary ◽  
First Principles ◽  
Boundary Surface ◽  
Grain Boundary Sliding ◽  
Excess Energy ◽  
First Principles Calculations ◽  
Perfect Single Crystal ◽  
Boundary Sliding ◽  
The Ideal

The grain boundary surface is the excess energy of the grain boundary as the lattice on one side of the grain is translated relative to the lattice on the other side of the grain. The maximum in the slope of the grain boundary surface determines the ideal shear strength for the grain boundary sliding. We presented the ideal shear strength for the grain boundary sliding in aluminum Σ3(11 2)[110] tilt grain boundary from the first-principles calculations. The ideal shear strength for the grain boundary sliding was much smaller than the ideal shear strength of a perfect single crystal.

First-Principles Calculations of Stacking Faults and Grain Boundaries in Metals

1990 ◽  
Vol 213 ◽  
Author(s):  
K. Hampel ◽  
D.D. Vvedensky ◽  
S. Crampin
Keyword(s):  
Magnetic Properties ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
First Principles ◽  
Stacking Faults ◽  
First Principles Calculations ◽  
Comprehensive Description ◽  
Planar Defects ◽  
Detailed Understanding ◽  
Defect Energies

ABSTRACTA detailed understanding of planar defects plays an important role in the search for a comprehensive description of the mechanical behaviour of metals and alloys. We present calculations for isolated stacking faults and grain boundaries using the layer Korringa-Kohn-Rostoker method including an assessment of the force theorem, which has already proven itself in evaluating defect energies for elemental close-packed metals. These ab initio total energy calculations will be supplemented by a study of the changes in bonding and local magnetic properties near a symmetric Σ5 (310) grain boundary in Fe

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